A fixing part of copying machines, etc. usually has the system shown in FIG. 8 from the standpoint of safety and economy, in which paper 33 having thereon toner image 32 is passed between fixing hot roller 30 and fixing pressure roller 31 whereby the toner image is fixed on the paper as fixed image 40 by applying heat (usually 170.degree. to 200.degree. C.) and pressure.
Fixing hot roller 30 used in this fixing system is generally composed of a base made of metals (e.g., aluminum), ceramics or heat-resistant plastics, i.e., roller core 34, having coated thereon a fluorine resin to a thickness of several dozens of microns to form release coat 35. In FIG. 8, numeral 36 denotes a core of pressure roller 31, 37 denotes a core of pressure roller 31, 38 and 39 each denotes a scraper, and 41 denotes a heater.
Where the fluorine resin coat on a cylindrical core, such as a core of a fixing roller, is formed by spray coating or electrostatic coating of a resin dispersion followed by baking, the baked resin coat has large roughness so that surface finishing by polishing is needed. In some cases, the baked and polished coat must be re-baked to remove the scratches caused by polishing.
On the other hand, the fluorine resin coat can also be formed by transfer coating in which a resin dispersion in a coating pan is once picked up with a transfer roller and the transfer roller having the resin dispersion thereon is brought close to a core to transfer the resin dispersion to the core. According to the transfer coating system, since the baked resin coat has a uniform and smooth surface free from waviness, there is no need to polish and re-bake the baked coat. However, when the transfer of the fluorine resin dispersion from the transfer roller to the core is cut off, a part of the coat has a larger coating build-up, making it difficult to obtain a uniform coat thickness over the entire coated area. The difference in coat thickness between such a build-up part and the rest sometimes reaches 30 .mu.m or more. This being the case, the resulting resin-coated roller, when used as a fixing roller of a copying machine, causes copying disorders, such as poor fixing of a toner image and wrinkles of copying paper, or problems of appearance, such as a difference in color density between the part having a larger coating build-up and the part of smaller coating build-up or development of streaks.